5 resultados para full-scale testing

em Dalarna University College Electronic Archive


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The main aim of this project is to develop an ESES lab on a full scale system. The solar combisystem used is available most of the time and is only used twice a year to carry out some technical courses. At the moment, there are no other laboratories about combisystems. The experiments were designed in a way to use the system to the most in order to help the students apply the theoretical knowledge in the solar thermal course as well as make them more familiar with solar systems components. The method adopted to reach this aim is to carry out several test sequences on the system, in order to help formulating at the end some educating experiments. A few tests were carried out at the beginning of the project just for the sake of understanding the system and figuring out if any additional measuring equipment is required. The level of these tests sequences was varying from a simple energy draw off or collector loop controller respond tests to more complicated tests, such as the use of the ‘collector’ heater to simulate the solar collector effect on the system. The tests results were compared and verified with the theoretical data wherever relevant. The results of the experiment about the use of the ‘collector’ heater instead of the collector were positively acceptable. Finally, the Lab guide was developed based on the results of these experiments and also the experience gotten while conducting them. The lab work covers the theories related to solar systems in general and combisystems in particular. 

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In this paper, Finite Element method and full-scale experiments have been used to study a hot forging method for fabri-cation of a spindle using reduced initial stock size. The forging sequence is carried out in two stages. In the first stage, the hot rolled cylindrical billet is pre-formed and pierced in a closed die using a spherical nosed punch to within 20 mm of its base. This process of piercing or impact extrusion leads to high strains within the work piece but requires high press loads. In the second stage, the resulting cylinder is placed in a die with a flange chamber and upset forged to form a flange. The stock mass is optimized for complete die filling. Process parameters such as effective strain distribution, material flow and forging load in different stages of the process are analyzed. It is concluded from the simulations that minor modifications of piercing punch geometry to reduce contact between the punch and emerging vertical walls of the cylinder appreciably reduces the piercing load. In the flange chamber, a die surfaces angle of 52° instead of 45° is pro-posed to ensure effective material flow and exert sufficient tool pressure to achieve complete cavity filling. In order to achieve better compression, it is also proposed to shorten both the length of the inserted punch and the die “tongues” by a few mm.

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Syftet med denna studie var att komma fram till om kedjeföretag inom detaljhandeln intagit ett serviceperspektiv, där fokus ligger på relationer. Detta genom att undersöka hur aktörerna använder sin frontlinjepersonal. En kvalitativ flerfallstudie har genomförts där tre kedjeföretag bidragit med information rörande transaktions- eller relationsorienterad försäljning, medarbetarskap och betraktande av frontlinjepersonalen. Utgångspunkten för analys av fallstudierna har varit två intervjuer per företag. Dels med butikens högste chef samt med en medarbetare. Det teoretiska ramverket i denna studie rörande medarbetarskap, skapande av värde/nytta för kund samt intern marknadsföring som möjliggör att kund upplever hög tjänstekvalité, signalerar ett tankesätt inom ett serviceperspektiv och används för att svara på syftet. Huruvida kedjeföretagen intagit ett serviceperspektiv fullt ut, är inte möjligt att konkludera i denna småskaliga forskningsuppsats. Vidare forskning är nödvändig. Resultatet från de undersökta företagen i denna studie visar på tendenser till att utveckla ett serviceperspektiv med fokus på goda kundrelationer, vilket är det som skall ge framgång. De undersökta kedjeföretagen skiljer sig dock åt vad gäller intagandet av ett serviceperspektiv. Exempelvis förlitar sig ett företag alltjämt till lågt pris och produktens egenskaper som primära faktorer för intäktsskapande, medan andra premierar det personliga mötet.

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In this thesis the solar part of a large grid-connected photovoltaic system design has been done. The main purpose was to size and optimize the system and to present figures helping to evaluate the prospective project rationality, which can potentially be constructed on a contaminated area in Falun. The methodology consisted in PV market study and component selection, site analysis and defining suitable area for solar installation; and system configuration optimization based on PVsyst simulations and Levelized Cost of Energy calculations. The procedure was mainly divided on two parts, preliminary and detailed sizing. In the first part the objective was complex, which included the investigation of the most profitable component combination and system optimization due to tilt and row distance. It was done by simulating systems with different components and orientations, which were sized for the same 100kW inverter in order to make a fair comparison. For each simulated result a simplified LCOE calculation procedure was applied. The main results of this part show that with the price of 0.43 €/Wp thin-film modules were the most cost effective solution for the case with a great advantage over crystalline type in terms of financial attractiveness. From the results of the preliminary study it was possible to select the optimal system configuration, which was used in the detailed sizing as a starting point. In this part the PVsyst simulations were run, which included full scale system design considering near shadings created by factory buildings. Additionally, more complex procedure of LCOE calculation has been used here considered insurances, maintenance, time value of money and possible cost reduction due to the system size. Two system options were proposed in final results; both cover the same area of 66000 m2. The first one represents an ordinary South faced design with 1.1 MW nominal power, which was optimized for the highest performance. According to PVsyst simulations, this system should produce 1108 MWh/year with the initial investment of 835,000 € and 0.056 €/kWh LCOE. The second option has an alternative East-West orientation, which allows to cover 80% of occupied ground and consequently have 6.6 MW PV nominal power. The system produces 5388 MWh/year costs about 4500,000 € and delivers electricity with the same price of 0.056 €/kWh. Even though the EW solution has 20% lower specific energy production, it benefits mainly from lower relative costs for inverters, mounting and annual maintenance expenses. After analyzing the performance results, among the two alternatives none of the systems showed a clear superiority so there was no optimal system proposed. Both, South and East-West solutions have own advantages and disadvantages in terms of energy production profile, configuration, installation and maintenance. Furthermore, the uncertainty due to cost figures assumptions restricted the results veracity.

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OBJECTIVE: to explore perspectives and experiences of antenatal care and partner involvement among women who nearly died during pregnancy ('near-miss'). DESIGN: a study guided by naturalistic inquiry was conducted, and included extended in-community participant observation, semi-structured interviews, and focus group discussions. Qualitative data were collected between March 2013 and April 2014 in Kigali, Rwanda. FINDINGS: all informants were aware of the recommendations of male involvement for HIV-testing at the first antenatal care visit. However, this recommendation was seen as a clear link in the chain of delays and led to severe consequences, especially for women without engaged partners. The overall quality of antenatal services was experienced as suboptimal, potentially missing the opportunity to provide preventive measures and essential health education intended for both parents. This seemed to contribute to women's disincentive to complete all four recommended visits and men's interest in attending to ensure their partners' reception of care. However, the participants experienced a restriction of men's access during subsequent antenatal visits, which made men feel denied to their increased involvement during pregnancy. CONCLUSIONS: 'near-miss' women and their partners face paradoxical barriers to actualise the recommended antenatal care visits. The well-intended initiative of male partner involvement counterproductively causes delays or excludes women whereas supportive men are turned away from further health consultations. Currently, the suboptimal quality of antenatal care misses the opportunity to provide health education for the expectant couple or to identify and address early signs of complications IMPLICATIONS FOR PRACTICE: these findings suggest a need for increased flexibility in the antenatal care recommendations to encourage women to attend care with or without their partner, and to create open health communication about women's and men's real needs within the context of their social situations. Supportive partners should not be denied involvement at any stage of pregnancy, but should be received only upon consent of the expectant mother.